38 POACEAE. 



50. TRIDENS R. & S. 



Second empty glume i -nerved. . 1. T. mulicus. 



Second empty glume 3-5-nerved. 2. T. elongatus. 



1. Tridens muticus (Torr.) Nash. {Triodia muiica Benth.) On dry hills 

 from Tex. to Colo, and Ariz.; also northern Mex. — Canon City {Porter). 



2. Tridens elongatus (Buckley) Nash. On plains and prairies from Tex. 

 to Colo, and Ariz. — Alt. about 5500 ft. — Pueblo; Canon City. 



51. DIPLACHNE Beauv. 



I. Diplachne acuminata Xash. In wet places from Ark. to Neb. and Colo. 

 — Alt. 4000-5500 ft. — New Windsor, Weld Co. ; Canon City. 



52. REDFIELDIA Vasey. 



I. Redfieldia flexuosa (Thurb.) Vasey. {Graphcphorum flcxuasum Thurb.) 

 In sand-hills from S. D. to Ind. Terr, and Tex. — Alt. 4000-5500 ft. — Sterling, 

 Logan Co. ; Fort Garland. 



53. KOELERIA Pers. Prairie-grass, June-grass. 



I. Koeleria cristata (L.) Pers. On prairies and plains from Ont. to B. C, 

 Pa. and Calif. A very variable species and perhaps a composite one. The 

 form common in the Rocky Mountain region has narrow, involute, glabrous 

 or puberulent leaves and narrow panicle, and has been described under the 

 name K. nitida Nutt. — Alt. 4000-10,000 ft. — Middle Park ; Pagosa Springs ; 

 vicinity of Boulder; foot-hills, Larimer Co.; Arboles; Gunnison; Sangre de 

 Cristo Creek ; Golden ; Twin Lakes ; Mancos ; Crystal Park ; Minnehaha ; 

 Cimarron; vicinity of Ouray; near Pike's Peak; Stove Prairie Hill, Larimer 

 Co. ; La Veta ; Manitou ; North Park ; Happy Hollow ; Hotchkiss ; Horse- 

 tooth Gulch; Table Rock; Manitou Junction; Dixon Cafion; hills about 

 Dolores; dry hills along Trail Creek; Como; Grizzly Creek; Fort Collins; 

 Hardin's ranch; Willow Creek, Routt Co. 



54. ERAGROSTIS Beauv. Skunk-grass. Stink-grass. 



Culm often decumbent at the base, much' branched, 1-5 dm. high; annuals; 

 panicle green. 

 Spikelets 1.5 mm. or less wide ; palet remaining attached to the continuous 



rachis, after the flowering glume has fallen. i. E. Pnrshii. 



Spikelets 2.5-5 mm. wide ; palet falling with the flowering glume and the inter- 

 nodes of the rachis. 2. E. major. 

 Culm erect, rigid, simple ; perennial ; panicle purple. 3. E. pectinacea. 



1. Eragrostis Purshii Schrad. In dry or sandy places from Ont. to Wash., 

 Fla. and Calif. — Alt. 4000-7500 ft. — Alamosa, Conejos Co.; Caiion City, Fre- 

 mont Co. ; along the river. Ft. Collins. 



2. Eragrostis major Host. {E. poacoidcs megastachya A. Gray.) Natural- 

 ized from Europe, in waste places and fields froin Ont. to Wash., Fla. and 

 Calif. — Alt. 4000-6000 ft. — Vicinity of Boulder; Longmont; New Windsor, 

 Weld Co. ; Cai'ion City, Fremont Co. ; Cheyenne Mountain ; Tobe Miller's 

 ranch ; near Ft. Collins. 



